Convenient Prayer?

I realised that we often pray only when we are convenient. We pray when we have the time or when we have a need. We reserve the leftover of our time for God. Sometimes, we are so tired when we come to God in prayer. But our prayer should be deliberate. We should learn to put down the things we need to do and offer the best time to God. The next time we pray, think, is it convenient prayer or costly prayer? When we pray convenient prayer, we may not grow so much spiritually because we are always feeding our ego as we pray. Only when our prayer is costly, we would become more like Jesus–more and more selfless.